Combined drsll and countersink



(No Model.) v 0. P. RUSSELL.

commi-:D DRILL AND GOUNTBRSINK.

No. 3037.053. Paten'tedAug. 5, 1884.

` bolt.

laina-nner as UNITED STATES CHARLES l?. RUSSELL, OF GREENFIELD,

PATENT Crrics.

MASSACHUSETTS, ASSIGNOR TO THE COMBINED DRiLL AND COUNTERSiNK.

.crearne-:Arron forming part of Letters Patent No. 303,053, dated August 5, 1884:.

Application filed January 52, 18S4 l (No model.)

. f'o @ZZ when/1, t may concern.-

` Be it known that I, CHARLES l?. RUSSELL, a citizen of the United States, residing at Greenfield, in the county of Franklin and State of lllassachusetts, have invented certain new and useful Improvements in apConibined Drill and Countersink; andl do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled inthe art to which it appertains to make and' use the same;

My vinvention relates Vto that class of drills which are made use of for .boring holes in metal or hard substances; and'the nature thereof consists inv combining with the drill a conical cutter oi'pecnliar construction for chan'ii'ering the edge of the hole cut by the drill, and thus forming a countersink or en largement toreceive the head of a screw or The points oi' the conical cutter or countersink reach below the cutting-line of 'thedrilh and are formed in such a manner that though the drill maybe passed it will not readily turn. rI he steel'which lies in the flirting of the drill and within the circle cut vents its breaking, and insures cutting a perfeet hole. y

ln the accompanying drawings, Figure l represents 4the countersinledrill with the parts thereof combined and ready for use. Fig. 2

illustrates the countersinh detached from the drill.

A designatesa twist-drill of the usual form, andf is a hollow cylinder having one of its ends chanifered or beveled to a proper angle. This chainfered or beveled edge is formed by turning a conical surface, b, and filing upon it depressions a in such a manner as to form cutters for chaniiering orenlarging the hole cut by the drill. These cutters are provided with projections or teeth s, which fit within the spiral grooves or flutings of the drill in such to permit it to pass freely through the bore of the cylinder, and yet prevent it from turning or twisting. By this construction a tool is provided in which means are supplied for lengtheningand shortening the inner bv' it adds strength to 4the countersink, pre` or drilling bit, strengthening the cutting-point of the countersink, and preventing the drill from being turned.

The boring implement illustrated in the drawings is a twist-drill; but other drills may beV used, if preferred. The. cylinder upon which the chami'er-cutters or countersink is formed is provided with a hole or bore extending entirelyl through it from end to end,in order that a drill of any length can be passed through, and that the drill may be pushed back or drawn within the cylinder to allow of the cutting-edges of the countersink -being ground. l

Atool of the construction described is particularly applicable to the operation ofsecuring the tire to a carriage-wheel, although of course it may be used for many purposes'. Vhen used for this purpose, it is placed in a proper holder or machine, and rotated in suchv a manner' that the drill passes through thetire and fellies, while the cuttin g-ed ges ofthe hollow cylinder chainfer and enlarge the hole cut by the drill, and form a countersink or enlargement of the hole to receive the head of thetire or countersink headed bolt. The drill is secured to the cylinder, and relatively adjusted thereto by means of the set-screw D, which2 on being turned down, holds the drill in any desired position, and so that its end may be at any desired distance ironi the countersink.

Having'thus described my invention, l claim and desire to secure by Letters Patent- The combination oi' the 'twist-drill A, thc setscrew D, and the cylinderB, having abore extending entirely through it, and provided with cutters having inwardlylproiecting teeth s, which t within the spiral grooves of the drill in such a manner as to permit it to pass freely through the bore of the cylinder, and yet prevent it from turning, as and for the purposes described.

In testimony whereof `l adir: my signature in ypresence of two witnesses.

' CHARLES P. RUSSELL.

llitnesses:

J oHN PUTNAM, WILLIAM S. WrnLrnMs. 

